I totally made up the term, but power themes are what I think of when I see a proposal that’s a sure winner.
Writing Tip for Today: What does a power theme proposal look like?

• Empowerment. I believe that a power theme is all about reader empowerment. If you offer your reader a way out or up from their perceived problem, you are more likely to connect with that reader’s deep need to be understood and to be validated. Even a book of essays, such as Blue Like Jazz, succeeds as power-theme because it gives readers permission to ask questions about faith as it tells the author’s personal faith journey.
• Target Audience. A power theme speaks to the most readers within a tightly defined demographic. If you’re looking to lose weight or get in shape, for instance, you target the group most interested in these topics. If you think you can sell ice to Eskimos, research the demographic first. The publisher will need to see these kinds of stats, anyway.
• Gut-level Emotions. I’ve said this before, but even a nonfiction book about financial health will be more successful if it taps into some deeply held emotion. Belonging, Acceptance and Societal Status are all examples of wanting to be loved. If you can give the reader an emotional reason for reading your book, you unleash a powerful response. Even a book about the driest subject, when paired with these deep-seated emotions, can trigger a bigger connection for that reader. Then, the reader will be more likely to tell others, “You gotta read this book.”